package Day2025_03_22;

public class LeetCode97 {
    public boolean isInterleave(String s1, String s2, String s3) {
        int m = s1.length(), n = s2.length();
        if (m + n != s3.length()) return false;
        s1 = " " + s1;
        s2 = " " + s2;
        s3 = " " + s3;
        boolean[][] dp = new boolean[m + 1][n + 1];
        dp[0][0] = true;
        for (int i = 1; i <= m; i++) dp[i][0] = s1.charAt(i) == s3.charAt(i) && dp[i - 1][0];
        for (int i = 1; i <= n ;i++) dp[0][i] = s2.charAt(i) == s3.charAt(i) && dp[0][i - 1];
        for (int i = 1; i <= m; i++) {
            for (int j = 1; j <= n; j++) {
                dp[i][j] = (s1.charAt(i) == s3.charAt(i + j) && dp[i - 1][j]) || (s2.charAt(j) == s3.charAt(i + j) && dp[i][j - 1]);
            }
        }
        return dp[m][n];
    }

    public boolean isInterleave2(String s1, String s2, String s3) {
        int m = s1.length(), n = s2.length();
        if (m + n != s3.length()) return false;
        s1 = " " + s1;
        s2 = " " + s2;
        s3 = " " + s3;
        boolean[][] dp = new boolean[m + 1][n + 1];
        dp[0][0] = true;
        for (int i = 1; i <= m; i++) {
            if (s1.charAt(i) == s3.charAt(i)) dp[i][0] = true;
            else break;
        }
        for (int i = 1; i <= n ;i++) {
            if (s2.charAt(i) == s3.charAt(i)) dp[0][i] = true;
            else break;
        }
        for (int i = 1; i <= m; i++) {
            for (int j = 1; j <= n; j++) {
                dp[i][j] = (s1.charAt(i) == s3.charAt(i + j) && dp[i - 1][j]) || (s2.charAt(j) == s3.charAt(i + j) && dp[i][j - 1]);
            }
        }
        return dp[m][n];
    }

    public static void main(String[] args) {
        LeetCode97 leetCode97 = new LeetCode97();
        System.out.println(leetCode97.isInterleave("", "", "a"));
    }
}
